1. Field of Invention
The present invention relates to a semiconductor device in which contact holes in an insulating interlayer are used for electrical connections, and to an electro-optical unit and an electronic apparatus including the semiconductor device.
2. Description of Related Art
Recently, electro-optical devices including liquid crystal devices and electroluminescent (EL) display panels have become popular as display units of electronic apparatuses, such as mobile telephones, mobile computers, and video cameras. Such electro-optical devices have a plurality of elements including transistors and diodes mounted on a substrate to form predetermined circuits, and also have a plurality of wiring lines to electrically connect these elements.
In such wiring lines, lower and upper conductive layers having an insulating interlayer therebetween are electrically connected via a contact hole in the insulating interlayer. That is, with reference to FIGS. 16(A), 16(B), and 16(C), a substrate 240 has the following layers thereon: in order, a first conductive layer 210, an insulating interlayer 220 having a contact hole 221 therein at the position where it overlaps the first conductive layer 210 in plan view, and a second conductive layer 230 electrically connected to the first conductive layer 210 via the contact hole 221. In a known structure, both the first conductive layer 210 and the second conductive layer 230 overlap the entire contact hole 221 in plan view. Thus, the first conductive layer 210 is in contact with the second conductive layer 230 at the entire bottom area 222 of the contact hole 221. Herein, the second conductive layers 230 are, for example, a plurality of parallel wiring lines, and second conductive layers 250, which are also wiring lines, extend adjacent to the second conductive layers 230 in the same layer.